Pipe connecting structure for a heat exchanger

ABSTRACT

A pipe connecting structure for a heat exchanger having a header portion or manifold defined by a plurality of parallel elongate header tubes, connector block having a side face adapted to abut against a side region of an outer one of the header tubes and connection means configured to connect a pipe thereto, and joining means. The joining means include at least one elongate tubular member having a first end adapted to be inserted through a hole formed in a first side wall of at least the outer one of the header tubes, and a second end extending through a corresponding hole in the side face of the connector block, whereby the second end communicates with the connection means.

TECHNICAL FIELD OF INVENTION

The invention relates to a piping structure for a heat exchanger; more particularly, a simplified header construction having compact pipe connecting structure capable of withstanding high pressures.

BACKGROUND OF INVENTION

Heat exchangers are used in vehicles to cool engine coolant, to cool charge air and to heat and/or cool refrigerant in a vehicle air conditioning system. Such heat exchangers typically comprise upper and lower header tanks or manifolds having a plurality of fluid passages extending therebetween, air gaps, typically provided with strengthening ribs, are provided between the refrigerant passages to allow heat transfer between a flow of air passing through the air gaps and a flow of a fluid passing through the fluid passages.

Connection means are typically provided at ends of one or both of the header tanks for connecting to delivery and discharge conduits supplying fluid to be cooled/heated to and from the heat exchanger.

Typically such connection means are formed by brazing a pipe connection onto a connection block joined to an end region of a header tank. Such pipe connections are difficult to form in situe in the vehicle, particularly in the case of a heat exchanger (typically an evaporator) provided within a HVAC module of a vehicle air conditioning system, leading to packaging constraints due to the need for extended header tank end regions and fixed pipe routing. Such pipe connections can also lead to leakage problems, particularly where carbon dioxide is used as a refrigerant. When carbon dioxide is used as refrigerant, very high pressures in the range of up to more than 80 bar exist within the refrigerant circuit of the air conditioning system. The pressure loading on individual components of an air conditioning system therefore rises significantly.

What is needed is a more compact and reliable pipe connecting structure that provides more versatile pipe routing while better withstanding high refrigerant pressures while at the same time simplifying header construction.

SUMMARY OF THE INVENTION

According to the present invention there is provided a pipe connecting structure for a heat exchanger including a header portion or manifold defined by a plurality of parallel elongate header tubes; connector block having a side face adapted to abut against a side region of an outer one of the header tubes and connection means configured to connect a pipe thereto; and joining means including at least one elongate tubular member having a first end adapted to be inserted through a hole formed in a first side wall of at least the outer one of the header tubes, and a second end extending through a corresponding hole in the side face of the connector block, whereby the second end communicates with the connection means.

Preferably the at least one tubular member extends substantially perpendicular to the plurality of header tubes.

In one embodiment the first end of the at least one elongate tubular member is adapted to extend through a corresponding hole in a second side wall of the outer one of the header tubes diametrically opposite the first side wall and through an aperture in a side wall of the one of the plurality of header tubes furthest from the outer one of the header tubes, whereby the first end communicates with an interior of the furthest one of the header tubes, whereby the at least one tubular member of the joining means extends between, and perpendicular to, the plurality of elongate header tubes to connect the plurality of elongate pipes to one another and to the connector block.

Preferably the at least one tubular member of the joining means includes a radially extending flange located between the first and second ends and adapted to be positioned between sides faces of the furthest one of the header tubes and an adjacent header tube.

In one embodiment the header portion comprises two parallel elongate header tubes, a first tube corresponding to the outer one of the header tubes and a second tube corresponding to the furthest one of the header tubes, the radially extending flange being positioned between the first and second tubes.

Preferably the joining means comprises a plurality of parallel tubular members arranged in a plane containing the longitudinal axis of each of the plurality of header tubes of the header portion.

The connection means of the connector block may be adapted to receive the pipe with the pipe arranged parallel to the plurality of header tubes. Alternatively, the connection means of the connector block may be adapted to receive the pipe with the pipe arranged perpendicular to the plurality of header tubes.

In one embodiment the connection means of the connector block includes a flange or stub to be received within an end of the pipe. In an alternative embodiment the connection means includes an aperture for receiving an end of the pipe.

Further features and advantages of the invention will appear more clearly on a reading of the following detail description of the preferred embodiment of the invention, which is given by way of non-limiting example only and with reference to the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

Preferred embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a known pipe connecting structure for a heat exchanger;

FIG. 2 is a perspective view of a pipe connecting structure according to a first embodiment of the present invention;

FIG. 3 is an exploded view of the pipe connecting structure of FIG. 2;

FIG. 4 is a perspective view of a pipe connecting structure according to a second embodiment of the present invention;

FIG. 5 is an exploded view of the pipe connecting structure of FIG. 4;

FIG. 6 is a sectional view of the pipe connecting structure of FIG. 4 taken along line A-A;

FIG. 7 is a perspective view of a pipe connecting structure according to a third embodiment of the present invention;

FIG. 8 is a further perspective view of the pipe connecting structure of FIG. 7;

FIG. 9 is an exploded view of the pipe connecting structure of FIG. 6;

FIGS. 10 and 11 are exploded perspective views of a pipe connecting structure according to a fourth embodiment of the present invention;

FIG. 12 is a sectional view of the pipe connecting structure of FIG. 10 taken along line B-B and;

FIG. 13 is a detailed perspective view of the pipe connecting structure of FIG. 10 with the conduit omitted.

DETAILED DESCRIPTION OF INVENTION

In accordance with a preferred embodiment of this invention, FIG. 1 illustrates a typical cross flow heat exchanger 1 having a first and second spaced manifolds or header tanks 2,3 with a plurality of coolant or refrigerant tubes 4 extending therebetween, said refrigerant tubes 4 being separated by fins to enhance refrigerant to air heat transfer. Refrigerant flows between the manifolds 2,3 via the tubes 4.

Each manifold 2,3 is formed from two parallel header tubes 10,11, each header tube 10,11 of the first manifold 2 communicating with a respective header tube 12,13 of the second manifold 3 via a respective number of said refrigerant tubes 4. One of the two header tubes 10 of the first manifold 2 comprises a refrigerant delivery conduit and the other header tube 11 of the first manifold 2 comprises a discharge conduit. The second manifold 3 is provided with bridging passageways between its two constituent header tubes 12,13 to provide cross flow.

A refrigerant delivery line 14 is connected to the first header tube 10 of the first manifold 2 and a refrigerant discharge line 15 is connected to the second header tube 11 of the first manifold 2. Such connections are made by a connector block 16 joined to the ends the header tubes 10,11 beyond the block of refrigerant tubes 4, apertures being formed in such connection block into which are fixed, typically by brazing, the ends of the delivery and discharge lines 14,15.

The connector block 16 also has to serve as a support and spacer for the ends of the header tubes 10,11, the header tubes 10,11 requiring further support, spacing and joining means adjacent the ends of the header tubes remote from the connector block 16, this requiring further brazing and/or assembly steps.

As illustrated in FIGS. 2 and 3, in a first embodiment of the present invention, an improved pipe connecting structure comprises a connector block 110 having a side face 112 configured to abut against a side region 124 of a first header tube 100 and having an elongated aperture or row of holes formed in said face 112 for receiving the ends of joining members 130 a,130 b,130 c as will be described below.

Each joining member 130 a,130 b,130 c comprises a tubular body having a first portion 131 a,131 b,131 c, adapted to be inserted into a corresponding hole 103 a,103 b,103 c formed in a side wall of a second header tube 102, and a second portion 132 a,132 b,132 c, adapted to be inserted through diametrically opposed holes 101 a,101 b,101 c, formed in opposite side walls of the first header tube 100, whereby said second portion 132 a,132 b,132 c of the joining member 130 a,130 b,130 c extends through said first header tube 100 and into the connector block 110, thus providing fluid communication between the second header tube 102 and the connector block 110.

A radially extending flange 134 a,134 b,134 c is formed on each joining member 130 a,130 b,130 c between said first and second portions thereof to be positioned, in use, between the first and second header tubes.

An outer face 114 of the connector block 110 is provided with an aperture 116 for receiving a flattened end 142 of a delivery or discharge conduit 140.

During assembly, the connector block 110 can be secured to the header tubes by inserting a tool through the aperture 116 into at least one of the joining members whereby regions of the joining member on either side of the respective apertures in the header tubes and be expanded or clinched to lock the components together. The joining members 130 a,130 b,130 c, connector block 110 and the conduit 140 can then be sealed in their respective receiving apertures by brazing or by suitable adhesive.

Thus, a compact connecting structure is provided that serves to provide fluid connection between a delivery or discharge conduit and a header pipe of the manifold while at the same time supporting and correctly spacing the ends of the header tubes.

In a second embodiment, illustrated in FIGS. 4 to 6, the connector block 210 has a side face 212 configured to abut against a side region 224 of a first header tube 200 and having an elongated aperture or row of holes 211 a,211 b,211 c formed in said face 212 for receiving the ends of joining members 230 a,230 b,230 c.

As in the first embodiment, each joining member 230 a,230 b, 230 c comprises a tubular body having a first portion 231 a,231 b,231 c, adapted to be inserted into a corresponding hole 203 a,203 b,203 c formed in a side wall of a second header tube 202, and a second portion 232 a,232 b,232 c, adapted to be inserted through diametrically opposed holes 201 a,201 b,201 c, formed in opposite side walls of the first header tube 200, whereby said second portion 232 a,232 b,232 c of the joining member 230 a,230 b,230 c extends through said first header tube 200 and into the connector block 210, thus providing fluid communication between the second header tube 202 and the connector block 210.

Again, a radially extending flange 234 a,234 b,234 c is formed on each joining member 230 a,230 b,230 c between said first and second portions thereof to be positioned, in use, between the first and second header tubes.

In the second embodiment the connector block 210 comprises a substantially tubular body having an aperture 216 in one end face for receiving end 242 of a delivery or discharge conduit 240 such that said end of the conduit 240 is arranged parallel to the header tubes 200,202. An axial slot 244 is provided in the end of the conduit 240 for receiving the ends of the second portions 232 a,232 b,232 c of the joining member 230 a,230 b,230 c. The conduit 240 is formed with a bend spaced from said end 242. Such arrangement provides a degree of flexibility in the angle of the conduit extending from the manifold to provide more flexibility in installation of the heat exchanger by selecting the circumferential position of the slot 244 in the end of the conduit 240.

An aperture 205 is provided in an outer side of the connector block through which a tool can be inserted to deform or clinch the central joining member 230 b to lock the connector block 210 to the header tubes 200,202, the connecting structure being subsequently sealed by means of brazing or adhesive.

As shown in FIG. 6, the ends of the header tubes 200,202 are sealed by means of a plug 250.

In a third embodiment, illustrated in FIGS. 7 to 9, the connector 310 is again joined to the header tubes 300,302 by means of joining members 330 a,330 b, 330 c, each comprises a tubular body having a first portion 331 a,331 b,331 c, adapted to be inserted into a corresponding hole 303 a,303 b,303 c formed in a side wall of a second header tube 302, and a second portion 332 a,332 b,332 c, adapted to be inserted through diametrically opposed holes 301 a,301 b,301 c, formed in opposite side walls of the first header tube 300, whereby said second portion 332 a,332 b,332 c of the joining member 330 a,330 b,330 c extends through said first header tube 300 and into the connector block 310, thus providing fluid communication between the second header tube 302 and the connector block 310.

Again, a radially extending flange 334 a,334 b,334 c is formed on each joining member 330 a,330 b,330 c between said first and second portions thereof to be positioned, in use, between the first and second header tubes 300,302.

In the third embodiment, the connector block 310 is adapted to slidingly receive an end 342 of a delivery or discharge conduit 340 over a portion of the connector block 310. An axial slot 344 is provided in the end 342 of the conduit 340 to enable the conduit 340 to be slid over a substantially tubular portion 346 of the connector block 310, the tubular portion 315 having an opening 316 end to enable fluid communication between the conduit 340 and the joining members 330 a,330 b,330 c and hence the second header tube 302.

An aperture 305 is provided in an outer side of the connector block through which a tool can be inserted to deform or clinch the central joining member 330 b to lock the connector block 310 to the header tubes 300,302, the connecting structure being subsequently sealed by means of brazing or adhesive. A plug 350 is inserted into the ends of the header tubes 300,302 to close the tubes.

A fourth embodiment of the present invention is illustrated in FIGS. 10 to 13. In the fourth embodiment, the connector block 410 is adapted to provide fluid communication with the header tube 400 to which it is abutted.

The connector block 410 has a side face 412 configured to abut against a side region 424 of a first header tube 400 and having an elongated row of holes formed in said face 412 for receiving the ends of joining members 430 a,430 b,430 c as will be described below.

Each joining member 430 a,430 b,430 c comprises a tubular body having a first portion 431 a,431 b,431 c, adapted to be inserted into a corresponding hole 401 a,401 b,401 c formed in the side region 424 of the first header tube 400, and a second portion 432 a,432 b,432 c, adapted to be inserted into the corresponding hole in the connector block 410, thus providing fluid communication between the second header tube 102 and the connector block 110. The first portion 431 a,431 b,431 c of each joining member has a smaller diameter than the second portion 432 a,432 b,432 c to limit the insertion of each joining member into its corresponding aperture in the header tube 400.

An outer face 414 of the connector block 110 is provided with an aperture 416 for receiving a flattened end 442 of a delivery or discharge conduit 440.

During assembly, the connector block 410 can be secured to the header tubes by inserting a tool through the aperture 416 into at least the central one 430 b of the joining members to deform or clinch the end regions of the joining member to lock the components together. The joining members 430 a,430 b,430 c, connector block 410 and the conduit 440 can then be sealed in their respective receiving apertures by brazing or by suitable adhesive.

The plug 450 serves to close the ends of the header tubes while at the same time holding the two header tubes together at the correct spacing.

Thus, a compact face connecting structure is provided that can provide a pipe connection with the header tube either the closest or furthest from the connection block by the use of the appropriate joining members.

Various modifications and variations to the described embodiments of the inventions will be apparent to those skilled in the art without departing from the scope of the invention as defined in the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments.

While three parallel joining members are used in the described embodiments, it is envisaged that one or more member could be used or a single member in the form of a flattened pipe having a width in the axial direction of the header tubes greater than that in the radial direction of the header tubes. However, multiple small tubes provide greater resistance to high pressure than a single large joining member and thus are considered particularly suitable for use with carbon dioxide refrigerant.

Where the joining members 330 a,330 b,330 c extend though the first header tube 300 into the second header tube 302, they may be provided with radial apertures in their second portions 332 a,332 b,332 c if fluid communication between the connector block 310 and the first header tube 300 as well as the second header tube 302 is desired.

While this invention has been described in terms of the preferred embodiments thereof, it is not intended to be so limited, but rather only to the extent set forth in the claims that follow. 

1. A pipe connecting structure for a heat exchanger comprising:— a header portion or manifold defined by a plurality of parallel elongate header tubes; a connector block having a side face adapted to abut against a side region of an outer one of said header tubes and connection means configured to connect a pipe thereto; and joining means comprising at least one elongate tubular member having a first end adapted to be inserted through a hole formed in a first side wall of at least said outer one of said header tubes, and a second end extending through a corresponding hole in said side face of the connector block, whereby said second end communicates with said connection means.
 2. A pipe connecting structure as claimed in claim 1, wherein the at least one tubular member of the joining means extends substantially perpendicular to said header tubes.
 3. A pipe connecting structure as claimed in claim 2, wherein said first end of said at least one elongate tubular member is adapted to extend through a corresponding hole in a second side wall of said outer one of said header tubes diametrically opposite said first side wall and through an aperture in a side wall of the one of said plurality of header tubes furthest from said outer one of said header tubes, whereby said first end communicates with an interior of said furthest one of said header tubes, whereby the at least one tubular member of the joining means extends between, and perpendicular to, said plurality of elongate header tubes to connect the plurality of elongate pipes to one another and to the connector block.
 4. A pipe connecting structure as claimed in claim 3, wherein said at least one tubular member of the joining means includes a radially extending flange located between said first and second ends and adapted to be positioned between sides faces of said furthest one of said header tubes and an adjacent header tube.
 5. A pipe connecting structure as claimed in claim 4, wherein said header portion comprises two parallel elongate header tubes, a first tube corresponding to said outer one of said header tubes and a second tube corresponding to said furthest one of said header tubes, said radially extending flange being positioned between said first and second tubes.
 6. A pipe connecting structure as claimed in claim 2, wherein the diameter of said first end of said at least one tubular member is smaller than the diameter of said second end.
 7. A pipe connecting structure as claimed in claim 3, wherein the joining means comprises a plurality of parallel tubular members arranged in a plane containing the longitudinal axis of each of the plurality of header tubes of the header portion.
 8. A pipe connecting structure as claimed in claim 7, wherein the connection means of the connector block is adapted to receive said pipe with said pipe arranged parallel to said plurality of header tubes.
 9. A pipe connecting structure as claimed in claim 7, wherein the connection means of the connector block is adapted to receive said pipe with the pipe arranged perpendicular to said plurality of header tubes.
 10. A pipe connecting structure as claimed in claim 9, wherein said connection means comprises a flange or stub to be received within an end of the pipe.
 11. A pipe connecting structure as claimed in claim 10, wherein the connection means comprises an aperture for receiving an end of the pipe. 